With increasing development of technologies and techniques for handheld communications devices (a mobile phone, a PAD, and the like), consumers have increasingly high requirements on mobile phone appearance and communication quality. Mobile phone makers always devote themselves to a mobile phone architecture design that is based on a metal appearance design, for example, from an original metal frame to today's all-metal back cover.
In the prior art, to improve antenna performance, an antenna is formed mainly by disposing a slit on a metal frame or on a frame of an all-metal back cover. However, the slit is generally located at the bottom or on either side of the frame, and a user's finger easily touches the slit. When the user's finger touches the slit, severe frequency deviation may occur on the antenna, making signal quality sharply deteriorate by 20-30 dB, which is referred to as a so-called “death grip” and severely affects communication quality of a handheld communications device.